JPH04507047A - Process for producing porous ceramic granule materials for use as adsorbents and/or absorbents, in particular as animal bedding - Google Patents

Abstract

Disclosed is a process for the production of a porous granulated ceramic material with a pore size greater than 1 mm, in which clay is mixed with calcite, quartz sand, dolomite, feldspar, fireclay, kieselgur and/or sepiolite as aggregate material, with water, with a fluidizer and with a surface-active agent and foamed in the usual way. The foamed mixture is subsequently moulded, if required, to form clay mouldings, the mouldings dried at a temperature between room temperature and 200 DEG C, the dried mouldings crushed and sieved, if required, the sieving fines being returned to the starting mixture, and finally mouldings or the crushed mouldings within a given particle-size range are baked at a temperature above 600 DEG C. The porous material thus produced is intended for use as an adsorbent or absorbent, in particular animal litter. The starting materials are mixed in given proportions and the mouldings or crushed mouldings with a moisture content of 5-25 % are placed in a preheated oven and baked at a given temperature in the range between 750 and 1050 DEG C. The invention also includes subsequently manufactured products.

Description

[Detailed description of the invention] The present invention uses clay: calcite, quartz sand, dolomite, feldspar, chamotte as additives. , diatomaceous earth and/or Seviolite; water; mixed with peptizer and surfactant; in a dispersing device known per se under pressure (1 to 10 bar) with a supply of compressed air. ) at a temperature of room temperature to 95°C, and if desired, high viscosity and thixotropic, In order to prepare foamed dispersions that are inherently stable, agents that counteract the effect of deflocculants are added. and then the foamed mixture is optionally formed into a clay object having a certain shape. , this is dried at a temperature of room temperature to 200°C, and this dried shaped clay object is shaped into a desired shape. The fine powder is further ground and sieved, and the fine powder is added back to the raw mixture, followed by shaped clay objects and/or or crushed shaped clay objects with selected particle sizes at product temperatures above 600°C. Calcined at high temperatures, as an adsorbent or absorbent, especially as animal bedding or litter. A method for producing a porous ceramic granule material with a pore size < lim for use, and Concerning products manufactured in a similar manner.

For adsorbing and/or absorbing liquids and gases, and especially for animal bedding. Previously known inter alia from DE 34 14 985 A crushed, porous ceramic material produced by the method of ing. This material is in particular known from the prior art, for example calcium silicate hydrate. Inexpensive compared to other adsorbents and/or absorbents, product parameters and It has remarkable deformability, especially in terms of appearance. This material is particularly known for its water absorption capacity and Despite having advantageous properties in terms of odor and odor absorption, Ceramics manufactured by known methods for use as bedding or bedding It is felt that there is a need to further improve the material.

Therefore, an object of the present invention is to improve the water absorption capacity, odor absorption capacity, etc. of materials. In order to further improve the adsorptive properties and/or the porous structure of the absorbent particles, , is a further development of the known method.

This purpose is achieved according to the invention with 25-45% by weight of clay, 0-40% by weight of calcite. , quartz sand, dolomite, feldspar, chamotte, diatomaceous earth and/or ceviola 20-50% by weight water, 0.1-1.0% by weight peptizer and 0.1-50% by weight Shaped clay with 1.0% by weight surfactant and residual moisture of 5-25% by weight introducing the object and/or the crushed shaped clay object into a preheated kiln; Achieved by firing at a predetermined product temperature within the range of 750-1050°C .

In a preferred embodiment of the invention, an indirectly fired rotary kiln is used for the firing process. use

The calcined product is conveyed directly from the kiln into the cooling drum and indirectly cooled by air. It is particularly advantageous to spray water directly into it in parallel.

In addition, the present invention provides a method for producing bedding for animals, which can be produced by the method according to the present invention. It also relates to adsorbents and/or absorbents.

As a result of the amounts of raw materials selected according to the invention and the conditions during firing of the shaped clay object, Surprisingly, its porous internal structure is clearly further improved, especially more homogeneous water absorption capacity, odor adsorption, and other product properties related to its structure have been optimized. It will be done. This surprises ceramics experts. First, until now, the above Ceramic materials containing 5-25% moisture can be heated in a pre-heated container without significant deterioration. It is said that it can withstand the thermal shock when introduced into a point with a temperature of 700 to 800 degrees Celsius. was not considered. Secondly, especially as a result of the disclosure of DE 3414965 , when molded clay objects are treated at temperatures higher than 800°C, the material becomes brittle and internal damage occurs. surface area is reduced and the desired properties of the product as an adsorbent and/or absorbent are impaired. There was a preconception that it would have a beneficial effect. Therefore, the treatment according to the present invention The result is a much better, especially much more uniform, structure, and the manufacturing process is also more economical. It was quite surprising that it became so favorable.

Also, under the above manufacturing conditions, a favorable thermochemical influence on the color of ceramic fired materials It was also surprising that the effect of The iron content in clay is usually oxidation yields a red product, which is then reduced to a nearly white color. death However, in the ceramic firing process, direct firing generally occurs, so the The desired kiln atmosphere is adjusted by the kiln burner. The advantages according to the present invention In indirect firing, which is used in 5 to IO per ton of material, at least partial oxidation, i.e. of the product It is expected that red coloring will occur. However, under the given manufacturing conditions, contrary to expectations As is clear from the fact that the color of the final product becomes close to white, the iron in the clay is reduced. It will be done. The reason why this reduction occurs is not completely understood. However, some points factors, i.e. relatively short firing times, local inert gas/reactive gas formation and pore formation. steam and/or hydrogen formation within the kiln chamber and steam and/or hydrogen formation throughout the kiln chamber. or hydrogen formation, which largely neutralizes the oxidizing effect of oxygen. it is conceivable that.

Direct water sprinkling into the cooling drum, advantageously immediately following the firing of the shaped clay objects. Rapid cooling may occur and the product may drop from approximately 1000°C to 60°C within a few minutes. It is also considered extreme for such ceramic materials to be cooled to This is of great importance for economic reasons, as it has to be It was surprising that rapid cooling did not adversely affect product properties.

Example 400 kg of Unistarwald clay with a residual moisture of 10% was mixed with 200 kg of water. , and 460 kg of feldspar with a residual moisture content of 5%, and 2 kg of sodium polyphosphate. mixer with thorium and 4.5 kg of sodium dodecylsulfonate. Stir vigorously for about 5 minutes and mold the resulting highly thixotropic clay dispersion. Transfer to a device and feed into a drying device in the form of a string with a diameter of 1 cIl.

After reaching the desired residual moisture content, this expanded clay material is ground in a roller grinder. Ru. Subsequently, the pulverized foamed clay particles are separated in a sieving process, and the pulverized foamed clay particles are separated by a sieving process. Oan's Put the particle size part into the kiln, 1. The particle size portion less than Oav is returned to the raw material. luck in the kiln The expanded clay particles are placed in a continuously running kiln preheated to 750-1050°C. supply The fired ceramic products are transported directly from the kiln into a cooling drum where they are Sprinkle water directly into the drum in parallel with wet air cooling. After a few minutes, the product is sent to the packaging factory can be carried to.

The material produced in this way is characterized by the following parameters:

pH value near, 3-7.5 Water absorption crab 150-190% by weight Internal surface m: 100-20 [1m27g Pore diameter: <0.8mm The features of the invention described in this description and in the claims make it possible to implement various embodiments of the invention. Can be used alone and in any combination to represent

Summary book Clay; as additives calcite, quartz sand, dolomite, feldspar, chamotte, diatomaceous Mix soil and/or Seviolite; water; peptizer and surfactant; and then the foamed mixture is optionally formed into shaped clay objects. , this is dried at a temperature of room temperature to 200°C, and this dried shaped clay object is shaped into a desired shape. The fine powder is further ground and sieved, and the fine powder is added back to the raw mixture, followed by shaped clay objects and/or or milled shaped clay objects with selected particle sizes at temperatures above 600’C. Calcined at product temperature, as an adsorbent or absorbent, especially for animal bedding or bedding. A method for producing a porous ceramic granule material with a pore size < lam for use as The raw materials are used in a specific mixing ratio to create molded clay objects or crushed molded clay. The object was fed into a preheated kiln with a residual moisture content of 5-25% and heated to 750-10%. A method characterized by firing at a predetermined product temperature of 50"c, and its manufacture Products that can be manufactured by law.

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Claims (4)

[Claims] 1. Clay; as additives calcite, quartz sand, dolomite, feldspar, chamotte, silica Sow earth and/or sepiolite; water; mixed peptizer and surfactant; under pressure (1-10 bar) with a supply of compressed air in a dispersing device known per se. Foaming is carried out at a temperature between 0.5°C and 95°C, optionally a highly viscous, thixotropic, inherently safe product. In order to prepare a defined foamed dispersion, an agent that counteracts the effect of the peptizer is added, The foamed mixture is then optionally formed into a clay object having a certain shape, which is dried at a temperature of room temperature to 200℃, and the dried shaped clay object is powdered as desired. Crushing and sieving, the fine powder is added back to the raw mixture, followed by shaped clay objects and/or Crushed shaped clay bodies with selected particle sizes are baked at product temperatures above 600°C. for use as adsorbents or absorbents, especially as bedding or bedding materials for animals. 1. A method for producing a porous ceramic granule material with a pore diameter <1 mm, the method comprising: 5-45% by weight clay, 0-40% by weight calcite, quartz sand, dolomite, feldspar, Chamotte, diatomaceous earth and/or sepiolite, 20-50% water by weight, Using 0.1-1.0% by weight peptizer and 0.1-1.0% by weight surfactant. shaped clay objects and/or ground forms containing 5 to 25% by weight of residual moisture. The clay body is introduced into a preheated kiln and heated to a temperature within the range of 750-1050℃. A method characterized by firing the product at a predetermined temperature. 2. A claim characterized in that a rotary kiln with indirect combustion is used in the firing process. The method described in item 1. 3. The calcined product is conveyed directly from the kiln into the cooling drum and indirectly by air. Claims characterized in that water is directly injected into the drum in parallel with the cooling. The method described in Section 1. 4. It can be produced by the method described in any one of claims 1 to 3. Adsorbents and/or absorbents, especially for animal bedding.